Ebnest p



(No Model.) I

E. P. WARNER.

COMMUTATOR FOR DYNAMO ELEGTRIG MACHINES NO. 361,973.

Patented Apr. 26, 1887.

u. D. C.

UNITED STAT S PATENT OFFICE.

ERNEST P. NVARNER, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE WVESTERNELECTRIC COMPANY, OF SAME PLACE.

- COMMUTATOR FR DYNAMO-ELECTRIC MACHINES.

SPECIPICATION orming part o`f Letters Patent No. 361373, dated April 26,1887.

Application filed September 9,1886. Serial Ne. 213.178. (No model.)

To all whom it may concerm Be it known that 1, ERNEST P. VVARNER, acitizen of the United States, residing at Ohicago, in the County of Cookand State of Illinois, have invented a -certain new and usefulImprovement in Commutators for Dynamo- Electric Machines, of which thefollowing is a full, clear, concise, and exact description, referencebeing had to the accompanying drawings, forning a part of thisspeeification.

My invention relates to the construction of the commutators ofdynano-electric machines; and it consists in forming the center piece orhub of metal, preferably brass, about which an insulatingring,preferably of blocks' of wood bound together, is formed. The segmentsare attached to the outside of the insulatingring, as hereinafterdescribed.

My invention will be readily understood by reference to the accompanyingdrawings, in whichv Figure 1 is an outside end view of the commutatorremoved from its shaft. Fig. 2 is a longitudinal section thereof uponline X X of Fig. 1. Fig. 3 is an inner end elevation showing the mannerof attaching the wire to the segments. Fig. 4 is an enlarged sectionalView of one of the bands which bind together the blocks which make upthe insulating-ring.

Like parts are indicated by similar letters of reference in thedifferent figures.

The hub or center piece, a, is preferably formed of brass, and ispreferably provided with grooves b, which may be formed by means of amilling-maehine. The blocks c are inserted in these grooves, as shown,and each Secured to the hub by a screw, d. I have shown butone of thescrews din the drawings. Each screw d is deeply countersunk, as shown,and the space above plugged up with wood or other insulating material.After the pieces c are thus each secured in place the wooden wedges eare driven in and glued between the difi'erent blocks, so as to form acontinuous insulatingring. Other insulating material might be usedinstead of wood. The partiallyformed commutator is then placed inalathe, and grooves f, preferably three in number, are formed therein,and at the same time the outer surface is rendered truly cylindrical andprepared to receive the metal shell. I then wind a band,

g, preferably of brass, about the wood in each of the grooves, and overthe metallic bands I wind tightly wire, preferably brass. The wire thuswound on under tension is soldered to the underlying bands in thedifferent grooves. I then cover the wire with insulating-tape, and aboutthe tape I bind strong thread. Any

'other suitable baud or hoop might be used.

A shell of metal is then slipped over the outside of the wood, andsecured thereto by woodscrews. I insert the screws through the shell, sothat there may be four screws in each of the blocks c, as shown in Fig.2, in order that when the shell is divided into segments each segmentmay be firmly held in place. The shell thus placed over and Secured tothe insulatingring is divided into segments, a milling-nachine beingused'for this purpose.

The slots or divisions between the different segments h should be ofsufficient width to insulate the segments from one another.

The wires leading from the armature may be attached to the differentsegments h of the commutator by binding-screws z', as shown in Figs. 2and 3.

The slots formed by the milling-machine are filled with wcoden blocksIc, as shown, and then about the circunference I place the removablemetallic segments l. These piecesl are a little wider than theunderlying segments h. The blocks k are thus securely held in place.

Commutators thus constructed may be used upon different styles ofdynamo-electric machines, and are of greater strength, more durable, andless liable to become impaircd or injured than any commutators fordynamoeleetric machines with which I am familiar.

In case the entire center is of wood, as heretofore, the commutator isalmost sure to become tight upon the shaft, so that it can be removedonly with great difficulty.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The combination, with the center of hub a, of thewooden ring formed of blocks, and the segments attached to said ring,substantially as shown and described.

2. The combination, with the center piece Ioo provided with grooves, ofthe blocks inserted i thereto and bound together, and the segnentssupported by said nsulating-ring, substantially as shown and described.

3. The eombination, in a eonnutator, of 5 the segnents h, sepamted bybloeks k, and the external removable segments, Z, wder than theunderlying segments 71 whereby said bloeks k a'e retaiued in place,substzmtiallyas described. 4. In a commutator, the bloeks c, each se- IOcured to the hub, and the wedges e, glued be tween said bloeks to formtherewith :L wooden insulating-ring for supporting the segments, and thebands bonnd t'ghtly in grooves provided in said insulating-ring,substantally as 15 shown and described.

ERNEST P. ARNER witnesses:

GEORGE P. BARTON, CIIAS. A. J osLYN, J

